After you file

Once a tax return has been Accepted by the IRS or a State, TurboTax receives no further information concerning the tax return or the status of any tax refund.

 

The IRS will be sending a letter in the next few weeks explaining the changes they made to your tax return which resulted in the lower federal tax refund.  If you disagree with the IRS explanation there will be a procedure in the letter for you to use.